Employ green lacewing Chrysoperla rufilabris to control insect pests

Predatory green Lacewing, Chrysoperla rufilabris for the control of aphids and other soft-bodied insects- BugsForGrowers.com

 

Green lacewings are scientifically known as Chrysoperla rufilabris, and considered as one of the most aggressive predators of aphids but it can also munch on other soft- bodied insects such as whitefly larvae, scale insects and mealy bugs. This beneficial insect is a nocturnal predator meaning it is active during night–time.  As name implies, adult lacewings are green in color with two pairs of transparent wings, which are longer than their body (Fig.1).  Green lacewing adults are tiny about 0.5 inch long insects with big eyes and very long and thin antennae.  Green lacewing adults generally feed on nectar, pollen and honeydews but their larvae are predatory in nature.  Mature larvae of green lacewing are about 0.5 inch long, brown in color and look like small alligators.  The only larval stages of green lacewing are predatory in nature.

Green lacewings are predators of aphids

Fig. 1. An adult of aphid predatory green lacewing , Chrysoperla rufilabris

 

Predatory Green Lacewing, Chrysoperla rufilabris kill and feed on following insect pests and their stages

  • Eggs of different insect species
  • Immature stages of whiteflies
  • Mealybugs
  • Mites
  • Small caterpillars/larvae
  • The green apple aphid, Aphis pomi
  • The brown citrus aphis, Toxoptera citricida
  • Thrips

How Green Lacewing are applied in the field 

  • Green lacewings are commercially sold in three developmental stages including eggs, larvae and adults but only larval stages are predatory in nature.
  • Eggs of green lacewings can be placed directly in your garden and it would be beneficial if their hatching is coincided with the outbreak of target pests including aphids and other soft bodied insects so that the hatched larvae would have enough food to munch on and survive.
  • For quick control of aphids, green lacewing larvae are directly released on the heavily infested plants with aphids or other soft bodied insects.
  • If adults are released, they will mate and females will lay eggs on aphid infested plants. These eggs hatch into larvae, which will start feeding on different stages of aphids and other host insects.

How many Predatory Green Lacewings Chrysoperla rufilabris should be applied for effective control of insect pests?

As green lacewings are commercially available in three developmental stages including eggs, larvae and adults, the application rate varies with the developmental stage that you are going release in your garden (Table 1).

Table 1. Number of developmental stages applied to the pest targeted area

Pest incidence

Eggs/sqft area

Larvae/sqft area

Adults/4 sqft area

Low

5 bi-weekly for 3 times

1 bi-weekly for 3 times

1 bi-weekly for 3 times

Medium

10 weekly for 4 times

2 weekly for 4 times

2 weekly for 4 times

Heavy

20 bi-weekly for 5 times

4 bi-weekly for 5 times

4 bi-weekly for 5 times

 

How Green Lacewing work in the field

  • When eggs of green lacewings are placed in your garden they will hatch into larvae that look like a small alligator.
  • Green lacewing larvae are predatory in nature and generally called as “aphid lions” because they voraciously feed on aphids.
  • Generally for quick control of aphids, green lacewing larvae are directly released on the heavily infested plants with aphids or other soft bodied insects.
  • When adults are released, they will mate and females will lay eggs on aphid infested plants.  These eggs hatch into larvae, which will start feeding on different stages of aphids and other host insects.
  • Green lacewing larvae have curved jaws called mandibles that they use for catching and puncturing of their prey and then they suck body content of the punctured prey.
  • These predatory green lacewing larvae can destroy and eat over 200 aphids within a week.
  • The larval stage lasts 2-3 weeks and they performs as biological control agents at optimum temperature between 67-89°F (19-31.6°C) with a relative humidity of 30% or greater. However, these environmental conditions are not necessarily a prerequisite of their successful implementation.

Research papers

  1. Chen, T. –Y. and Liu, T.-X. 2001. Relative consumption of three aphid species by the lacewing, Chrysoperla rufilabris, and effects on its development and survival. BioControl 46: 481-491.
  2. Grasswitz, T.R. and Burts, E.C.  1995. Effect of native natural enemies and augmentative releases of Chrysoperla rufilabris Burmeister and Aphidoletes aphidimyza (Rondani) on the population dynamics of the green apple aphid, Aphis poMi De Geer. International Journal of Pest Management 41: 176-183.
  3. Michaud, J. P. 2001. Evaluation of green lacewings, Chrysoperla plorabunda (Fitch) (Neurop., Chrysopidae), for augmentative release against Toxoptera citricida (Hom., Aphididae) in citrus. Journal of Applied Entomology 125: 383–388.
  4. Stewart, C. D., Braman, S.K. and Pendley, A.F.  2002. Functional Response of the azalea plant bug (Heteroptera: Miridae) and a green lacewing Chrysoperla rufilabris (Neuroptera: Chrysopidae), two predators of the azalea lace bug (Heteroptera: Tingidae). Environmental Entomology 31:1184-1190.